FUNDAMENTAL STUDY ON NITRITE ION ANALYSIS IN HARDENED MORTAR

• INOUE Masumi

  KITAMI INSTITUTE OF TECHNOLOGY, School of Regional Innovation and Social Design Engineering（165, Koen-cho, Kitami-shi, Hokkaido 090-8507, Japan）

• CHOI Heesup

  KITAMI INSTITUTE OF TECHNOLOGY, School of Regional Innovation and Social Design Engineering（165, Koen-cho, Kitami-shi, Hokkaido 090-8507, Japan）

• SUDOH Yuhji

  NISSAN CHEMICAL CORPORATION, Chemicals Division. Basic Chemicals Department（2-5-1, Nihonbashi, Chuo-ku, Tokyo 103-6119, Japan）

Bibliographic Information

Other Title

• モルタル硬化体に含有する亜硝酸イオンの分析方法に関する基礎的検討

Abstract

The determination of nitrite ion in concrete is generally carried out in accordance with JCI or JIS standards. However nitrite ion is known to be relatively unstable；nitrite may be oxidized to nitrate when heated. Therefore, the effects of heat and other parameters during production（cutting and fine grinding）and extracting processes（in warm water）of samples on the analysis results is a cause for concern when using existing standards for nitrite ion analysis.<br/>In this study, we aim to clarify the effects of various parameters in the preparation process of analytical samples on the analysis results of nitrite ion in hardened mortar. The different parameters analyzed were：method of cutting and fine grinding, extraction time, temperature, and sample concentration. The amount of nitrite ion in each mortar sample was measured by ion chromatography. The effect of cutting method on the analytical result of nitrite ion was found to be small. Whereas, in the production process of fine grinding, the extraction rate of nitrite ion was higher when a disc mill was used instead of an iron mortar. In extraction process in warm water, the extraction rate of nitrite ion increased with an increase in the extraction time and the temperature. However, there was no change in the extraction rate when the extraction time was prolonged beyond 30 min. Furthermore, the extraction rate of nitrite ion showed an increasing trend with increase in the sample concentration. However, there was no change in the extraction rate when the mass ratio of powder to liquid was prolonged beyond 1：16.

Journal

• Cement Science and Concrete Technology

  Cement Science and Concrete Technology 72 (1), 144-150, 2019-03-29

  Japan Cement Association

Keywords

• Nitrite ion
• Sample preparation method
• Warm water extraction
• Hardened mortar
• Ion analysis

Details

• CRID: 1390001288142813952
• NII Article ID: 130007626877
• DOI: 10.14250/cement.72.144
• ISSN: 21873313
• ISSN: 09163182
• Web Site: https://www.jstage.jst.go.jp/article/cement/72/1/72_144/_pdf
• Text Lang: ja
• Data Source:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Disallowed